Oracle 12C R2-新特性-SQLPLUS提供檢視歷史命令的功能

lhrbest發表於2017-02-19
OracleSQL

Oracle 12C R2-新特性-SQLPLUS提供檢視歷史命令的功能

型別：原創 分類：Oracle 12c 2017-02-18 10:03 閱讀(37)次 評論(0)

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Oracle 12C R2-新特性-SQLPLUS提供檢視歷史命令的功能

使使用者能夠從當前會話的歷史記錄列表中執行，編輯或刪除先前使用的SQL * Plus，SQL或PL / SQL命令。 可以使用SET HISTORY命令在當前SQL * Plus會話中啟用或禁用HISTORY命令。

官方文件：


http://docs.oracle.com/database/122/SQPUG/HISTORY.htm#SQPUG-GUID-CCF9B047-3122-4644-BA06-5FA4B5812E9F


1  命令及功能

命令：HISTORY

功能：提供執行，編輯，刪除之前命令的功能。


2  使用方法

預設HISTORY是沒有開啟的。 



SQL> HIST 3 EDIT

SP2-1650: History is off, use "SET HIST[ORY] ON" to enable History.


2.1   開啟HISTORY

注意：預設記錄100條命令而不是命令列數。 



SQL> set history on


2.2   檢視狀態 


SQL> show hist;

history is ON and set to "2"


2.3   設定記錄命令條數 


SQL> set history 2;  --設定為2條記錄


2.4   檢視已記錄的命令 


SQL> hist

  1  show user

  2  select

     1

     from dual;


2.5   編輯之前的命令 

SQL> hist

  1  select

     1

     from dual;

  2  show sga;

SQL> hist 1 edit

SQL> hist

  1  show sga;

  2  select

     sysdate

     from dual;


2.6   刪除之前的命令 



SQL> hist

  1  show sga;

  2  select

     sysdate

     from dual;

SQL> hist 2 del[ete]

SQL> hist

  1  show sga;


2.7   執行之前的命令 


SQL> hist

  1  select

     1

     from dual;

  2  show sga;

SQL> hist 2 run

 

Total System Global Area 1308622848 bytes

Fixed Size	    8792440 bytes

Variable Size	  889194120 bytes

Database Buffers	  402653184 bytes

Redo Buffers	    7983104 bytes


標籤：SQLPLUS 歷史命令
本文連結：http://www.cndba.cn/Expect-le/article/1759

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Oracle 12C R2-新特性-SQLPLUS提供檢視歷史命令的功能  DBA筆試面試講解




HISTORY

Syntax 

HIST[ORY] [n RUN | EDIT | DEL[ETE]] | [CLEAR | LIST]

Enables users to run, edit, or delete previously used SQL*Plus, SQL, or PL/SQL commands from the history list in the current session. You can enable or disable the HISTORY command in the current SQL*Plus session by using the SET HISTORY command.

The HISTORY command enables you to:

  • List all entries in the command history list.

  • Run an entry in the command history list.

  • Edit an entry in the command history list.

  • Delete an entry from the command history list.

  • Clear all entries in the command history list.

Terms 

HIST[ORY]

Lists all entries in the command history list. 

n

Represents an entry in the command history list. An asterisk (*) indicates the last used command in the command history list. 

RUN

Enables you to execute entry n from the command history list. 

EDIT

Enables you to edit entry n in the command history list, using the default text editor. After you edit entry n in the command history list and save the changes, a new entry is created at the end of the list. When the number of entries in the command history list reaches the maximum limit, the oldest entry in the list will be cleared to accommodate the new entry. 

DEL[ETE]

Enables you to delete entry n from the command history list. After you delete an entry from the history list, the list is reordered to reflect the most recent changes. 

CLEAR

Enables you to clear all entries in the history list. Once cleared, the history list cannot be recovered. 

LIST

Lists all entries in the history list. This is the same as using the HIST[ORY] command by itself.

Usage

You can use the SQL*Plus DEFINE command to define the variable, _EDITOR, to hold the name of your preferred text editor. For example, to define the editor used by EDIT to be vi, enter the following command: 

DEFINE _EDITOR = vi

EDIT attempts to run the default operating system editor if _EDITOR is undefined. See the DEFINE command for more information.

Example 12-1 Examples

The following example executes the fifth entry in the history list: 

HIST[ORY] 5 RUN

The following example allows you to edit the third entry in the history list: 

HIST[ORY] 3 EDIT

The following example allows you to delete the second entry from the history list: 

HIST[ORY] 2 DEL[ETE]

The following example allows you to delete all entries from the history list: 

HIST[ORY] CLEAR

The following example shows you how to enable or disable command history, and how to check the command history status: 

SQL> set history on
SQL> show history
History is ON and set to "100"
SQL> set history off
SQL> show history
History is OFF
SQL> set history 1000
SQL> show history
History is ON and set to "1000"

The following example shows you how to list all entries in the history list: 

SQL> show history
History is ON and set to "100"
SQL> show user
USER is "SYSTEM"
SQL> desc dual
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 PROD                                               VARCHAR2(1)

SQL> select * from dual;

D
-
X

SQL> history 4 run

D
-
X

SQL> history
  1  show history
  2  show user
  3  desc dual
* 4  select * from dual;

An asterisk (*) indicates the last used command in the command history list.

The following example shows you how to list all entries in the history list, and then execute the second entry: 

SQL> history
  1  show history
  2  show user
  3  desc dual
* 4  select * from dual;
SQL> history 2 run
USER is "SYSTEM"
SQL> history
  1  show hist
* 2  show user
  3  desc dual
  4  select * from dual;


來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/26736162/viewspace-2133816/，如需轉載，請註明出處，否則將追究法律責任。

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